A US decision to waive sanctions against China for exporting missile technology shows the two countries are eager to keep their shaky relationship on track into the next US administration, analysts said.

The United States said late Tuesday it would lift sanctions on China imposed over sales of nuclear-capable missile technology to Pakistan and Iran, in return for a Chinese pledge to step up its curbs on sensitive exports.

But while letting Beijing off the hook, Washington announced it was imposing restrictions on Iran and Pakistan for purchasing the technology.

"The United States is trying to improve relations with China as the end of the Clinton administration is approaching," said Brian Bridges, an expert on Asian security at Hong Kong's Lingnan College.

This is just the latest in a series of moves aimed at keeping ties stable and reasonably friendly during the precarious transition from one US administration to another, he said.

As heads of states from the Asia-Pacific region met in Brunei last week, Chinese officials got repeated reassurances from US delegates that US policy on Taiwan would not change, regardless of who becomes president.

The US decision to scrap sanctions -- which is likely to mean the green light for US satellite launches from China -- was given after China promised to keep a closer eye on missile-related exports.

"China has no intention of assisting, in any way, any country in the development of ballistic missiles that can be used to deliver nuclear weapons," said foreign ministry spokesman Sun Yuxi.

"China will, based on its own missile non-proliferation policy and export control practices, further improve and reinforce its export control system," he added.

Sun said China would issue a comprehensive export control list of missile-related items, including dual-use technology.

Some analysts doubted if a promise by China would achieve anything, given its past record of selling sensitive technologies to rogue states in Asia despite repeated official denials.

"Chinese pledges are not worth the breath they are spoken in," said Richard Fisher, a senior fellow with the Washington-based Jamestown Foundation and a critic of the current US administration's engagement policy with China.

"Clinton's non-proliferation strategy has all along been to give something to China in return for nothing."

Last year, the US National Intelligence Council said it had concluded beyond doubt that China had transferred nuclear-capable M-11 missiles to Pakistan early in the 1990s.

And suspicions of continued Chinese aid to "countries of concern" in Asia are still lingering.

But even if China's new pledge does not have the force of law, it could be a crucial first step towards making Beijing a more active participant in efforts to curb proliferation.

"It's not that the whole problem has been solved," said Robert Karniol, the Bangkok-based Asia-Pacific editor of Jane's Defense Weekly.

"But if you can get a first commitment on the part of the Chinese, then you have a starting point."

At the same time as the United States erased sanctions against Beijing, it sharpened restrictions against Islamabad, banning exports of some technologies to the Pakistani defense ministry, its Space and Upper Atmospheric Research Commission and related units.

As Pakistan is a buyer of missile technology, not a supplier, this could signal a change in the US approach towards non-proliferation, analysts said.

"It might be the United States is shifting its focus from the supplier to the receiving end," said Bridges from Lingnan College.

"The thinking could be if Pakistan doesn't get the technology from China, it might get it from someone else."

But others argued there was little apparent logic in the decision to punish Pakistan and Iran, and not China.

"Sanctioning Pakistan without sanctioning China is like punishing the soldier without punishing the general," said Fisher of Jamestown Foundation -- BEIJING (AFP)